As far as I know, Dash > Shuttle Loop (both hits) is a KO combo. Not always strictly true, because it can be escaped in certain circumstances, but it does indeed combo and I think at some %s it's 100% true though I don't know if it overlaps with KO %s. So yeah, short story, it hits. It's completely inescapable in the hands of a good player. However, there's restrictions and specifics, which is what stops it being always a true combo.
First off, Dash and Shuttle have not been changed since release as far as I know. D Throw and F Throw (as the other reliable set-ups) also haven't been changed in a very long time if at all, so it's not that the combos have magically gotten worse.
Second, there are a few factors for Shuttle combos to work - most obviously %, then opponent DI and the set-up (But I'll only cover Dash, since that's the one you're questioning.).
%s obviously vary by character. If the opponent hits %s that are too high, then either the Shuttle Loop will whiff entirely after a set-up, or the first hit will knock them just too far. Obviously, you can get around that last point by changing up your set-up, with F-Throw being the most notoriously hard of the 3 regular set-ups to get work, but also the least expected. That being said, different Shuttle Loop combos carry on working for a while into varying KO %s, so just knowing your KO and combo %s is a big deal.
DI is pretty simple in theory, but hard in practice. You just follow their DI with the set-up and the tilt of the hits. Generally, I don't think it can be smash DI'd if you accommodate for it, it just requires precision. Something of note I found is that the set-ups generally have slightly more hitstun than you first think, so you might be trying to hit too early in fear of whiffing or while applying pressure, but in the process setting up a case where even if you follow your opponent's DI, hit 2 will likely whiff. The hitboxes in my experience can also be pretty deceptively small, so watch out for that when following DI, too. Overall though, you get used to this.
Lastly, the set-up, and again, I'll only talk about Dash. From what I understand, Dash isn't a singular "it hits at this angle and knockback" deal. According to
Kurogane Hammer's MK page (shoutouts, btw
@KuroganeHammer ), Dash has 3 different hitboxes depending on when/where you hit. IIRC, in terms of reliability, hitting late is better as a set-up than hitting early, with the "middle" hitbox being the worst. Just don't quote me on that, I'm not a pro MK player by any means. lol All that being said, paying attention to when you hit is important because you effectively have 3 different combos on your hands, and you need to know where to be for each to connect (Though, this is only really hugely noticeable with the late hit's differences.).
Generally speaking this means that, using dash, you have to prepare for not only one of 3 hitboxes, but opponent %
and DI. You have to assess
on hit "Where's the correct position to still connect Up B given these current conditions?". It might require a lot of trial and error, but generally speaking, you'll eventually catch on to when you can and can't KO from each set-up with Shuttle Loop. Though with a sharp mind, it's realistically "always, within %s that allow it". As an extra tip, keep an eye on opponent's animations to see how close your opponent is to being in tumble and not hitstun. Air Up B comes out frame 7, so you can pretty reliably spend your sweet time closing in and throw the move out when you see the hitstun start wearing off for optimal timing (Sometimes you'll need to go as far as to double jump to connect. So yeah, take your time. Don't pressure yourself.).
As for where to be when the actual Shuttle Loop starts, a lot of people seem to start the move far too early and end up starting too far below their opponents, or too far away, which is probably what makes the move whiff so much for them. As mentioned before, you can hit with the first hit in such a way that hit 2 will just never connect (I actually had a few labbing cases where the opposite happened, and only hit 2 would connect, but... -totally different and mostly a non-issue.). Remember to get as high up as possible before you Up B and learn the general horizontal distance you need to be at for it to connect in the first place. -and (using the Dash example again) it's no use running into place to follow up from an early dash attack if the hit was late since they're two totally different combos in terms of positioning.
As extra tips for hitting/KOing with Shuttle Loop:
- Don't be afraid at lower %s to throw U Airs in the middle of this combo (My first ladder KO was post-nerf. I speak from experience. lol). Don't go crazy with them, but a single U Air > Up B can still a true combo from a few set-ups.
- If you're unsure you'll combo the Loop from a set-up (Like if you reacted slightly too late to which hitbox of Dash connected.), slow down and don't overextend yourself, expect an air-dodge and look for an opening.
- Remember not to overuse it for damage, or it'll stale - it's a KO move for a reason. Generally speaking, if you can N-air your opponent, it's probably better to do so since there's only a 2% difference, and it leaves your Loop fresh for KOing. It probably seems obvious, but you can get into a bad Shuttle Loop habit once you start nailing the combo.
That's all my knowledge on the subject, so I hope I broke it down well enough for you! Jump into training mode and get a feel for how long you have to connect at certain %s, and where you should be after each followup, and you should be set!
(I also hope I was accurate on all my info, my MK is admittedly rusty. lol)
